- * Dropped support for protocol versions less than 20
- (2.3.0 released 15 Mar 1999) and activated warnings for
- protocols less than 25 (2.5.0 released 23 Aug 2001)
- (Wayne Davison and J.W. Schultz, severally)
-
- * More optimal data transmission for --hard-links (protocol 28).
-
- * More optimal data transmission for --checksum (protocol 28).
-
- * Less memory is used when --checksum is specified.
-
- * Less memory is used in the file list (a per-file savings).
-
- * The generator is now better about not modifying the file list
- during the transfer in order to avoid a copy-on-write memory
- bifurcation (on systems where fork() uses shared memory).
- Previously, rsync's shared memory would slowly become unshared,
- resulting in real memory usage nearly doubling on the receiving
- side by the end of the transfer. Now, as long as permissions
- are being preserved, the shared memory should remain that way
- for the entire transfer.
-
- * Changed hardlink info and file_struct + strings to use
- allocation pools. This reduces memory use for large file-
- sets and permits freeing memory to the OS. (J.W. Schultz)
-
- * The 2 pipes used between the receiver and generator processes
- (which are forked on the same machine) were reduced to 1 pipe
- and the protocol improved so that (1) it is now impossible to
- have the "redo" pipe fill up and hang rsync, and (2) trailing
- messages from the receiver don't get lost on their way through
- the generator over to the sender (the latter mainly affected
- hard-link messages and verbose --stats output).
-
- * The reading & writing of the file-list in batch-mode is now
- handled by the same code that sends & receives the list over
- the wire. This makes it much easier to maintain.
-
- * Improved the internal uid/gid code to be more portable and
- a little more optimized.
-
- * The device numbers sent when using --devices are now sent as
- separate major/minor values with 32-bit accuracy (protocol 28).
- Previously, the copied devices were sent as a single 32-bit
- number. This will make inter-operation of 64-bit binaries more
- compatible with their 32-bit brethren. Note that optimizations
- in the binary protocol often sends the device data using fewer
- bytes than before, even though more precision is now available.
-
- * Some cleanup of the exclude/include structures and its code
- made things clearer, simpler, and more efficient.